1. Field of the Invention
The present invention relates generally to a parts feeding apparatus used in connection with application of parts varying in type depending on the type of products to which the parts are to be applied, and capable of automatically changing or switching the parts from one type to another according to a production control procedure or system. More particularly, the present invention relates to a parts feeding apparatus particularly suitable for use in the production of a wide variety of articles produced in relatively small lots.
2. Description of the Prior Art
There have been proposed various parts feeding apparatus suitable for use in the production of various articles produced in small lots. One such apparatus disclosed, for example, in Japanese Patent Laid-open Publication No. 3-57402 is designed to feed sliders for slide fasteners. The disclosed apparatus comprises a slider inventory unit including a plurality of guide rails arranged in parallel to one another, each releasably holding thereon rows of sliders of a different type, a slider conveying unit for capturing and conveying sliders one at a time from a selected one of the guide rails, and a slider guide unit for receiving the sliders conveyed one at a time from the slider conveying unit. The sliders received in the slider guide unit are conveyed one by one to a slider applying machine.
Another parts feeding apparatus disclosed, for example, in Japanese Utility Model Laid-open Publication No. 3-41710 includes a plurality of parts feed chutes arranged horizontally in parallel to one another. The chutes have respective downstream ends pivotally movable, as a single unit, in the same plane so that they come to communicate with a parts supplying holder to feed parts of different types selectively to the parts supplying holder.
In the parts feeding apparatus disclosed in the aforesaid Japanese Patent Laid-open Publication No. 3-57402, a plurality of rows of sliders of different types are stocked in parallel to one another with all the sliders in each row being of the same type. Accordingly, as the number of the type of sliders to be fed increases, the necessary space for installation of the rails increases. In addition, from the inventory unit to the guide unit, the sliders are conveyed one by one by a mechanical means. It is difficult to speed up the conveying speed by using such a mechanical conveying means, which further require a mechanism extremely complicated in construction.
On the other hand, the case of the parts feeding apparatus disclosed in the aforesaid Japanese Utility Model Laid-open Publication No. 3-41710, the number of the chutes increases with an increase in number of the type of parts to be fed. With an increase in number of the chutes, the over-all width of pivotal movement of the parallel juxtaposed chutes is necessarily enlarged. Accordingly, when the downstream end of each chute come to communicate with the parts applying holder, the chutes and the parts supplying holder form a great crossed axes angle with the result that smooth delivery of the parts from the chute to the parts supplying holder cannot be achieved. In view of this difficulty, only a limited small number of chutes can be used. Accordingly, the disclosed parts feeding apparatus appears to be unsuitable for supplying a wide variety of parts.
Furthermore, neither of the conventional apparatus described above is adaptable to the production of articles to be manufactured in relatively large lots.